There has been some suggestion that Baird’s and Arnoux’s Beaked Whales may be the same species, but analysis of mitochondrial and nuclear intron sequence data has revealed multiple fixed genetic differences, confirming that these species are reproductively isolated and valid taxonomic entities (Dalebout 2002).

Justification:
There is limited information on global abundance and none on trends in abundance for this species. It is not believed to be uncommon but it is potentially vulnerable to low-level threats and a 30% global reduction over three generations (81 years; Taylor et al. 2007) cannot be ruled out (criterion A).

Baird's beaked whales are found in deep oceanic waters of the North Pacific Ocean and the adjacent Japan, Okhotsk, and Bering Seas. Their range extends to the southern Gulf of California in the eastern Pacific, and to the island of Honshu, Japan in the western Pacific. They may occur in the vicinity of drift ice in the northern Sea of Okhotsk. Off the Pacific coast of Japan, they migrate into waters over the continental slope from May to October, but where they go in winter is not known. They also occur in the Sea of Japan. Their distributional limits in oceanic waters of the mid-Pacific are also not well known (Balcomb 1989; Kasuya 2002).

Three subpopulations of Baird’s beaked whales are recognized in the western North Pacific (Sea of Japan, Okhotsk Sea, and Pacific Ocean), where these whales have been exploited for centuries. There are an estimated 1,100 Baird’s beaked whales in the eastern North Pacific, including about 228 (CV=51%) off the US west coast (Barlow et al. 2006, Caretta et al. 2006). Abundance in Japanese waters has been estimated at about 7,000 individuals (5,029 off the Pacific coast, 1,260 in the eastern Sea of Japan, and 660 for the southern Okhotsk Sea – Miyashita 1986; Kasuya 2002; Barlow et al. 2006). These are likely underestimates because visual survey methods often do not account for the fact that the whales dive for long periods and are inconspicuous when they surface (Barlow 1999). There is no information on trends in the global abundance of this species.

Though they may be seen close to shore where deep water approaches the coast, Baird's beaked whales' primary habitats appear to be over or near the continental slope and near oceanic seamounts (Kasuya 2002) in temperate oceanic waters 1,000 to 3,000 m deep. Off the Pacific coast of Japan, these whales have been recorded in waters ranging between 23°C and 29°C, with a southern limit lying at the 15°C isotherm at a depth of 100 m. In the northern Okhotsk Sea the species has been recorded in waters less than 500 m deep, which could be explained by the availability of prey species in shallower waters at higher latitudes (Reyes 1991).

Baird's beaked whales feed mainly on deepwater and bottom-dwelling gadiform fishes, cephalopods, and crustaceans (Balcomb 1989; Kasuya 2002), as well as some pelagic fish, such as mackerel, sardines, and saury. The diet off the Pacific coast of Japan consists of 82% fish and 18% cephalopods, while in the southern Sea of Okhotsk the proportions are 13% and 87%, respectively. They may do much of their feeding at depths of 800-1,200 m.

Baird’s beaked whales are one of the few species of ziphiids to be commercially hunted (Kasuya 2002; Kasuya and Ohsumi 1984). Small numbers have been hunted by the Soviets, Canadians and Americans, whereas hunts by Japan have been major. The Japanese fishery started in the early 1600s and underwent several expansions and declines. At its peak, after World War II, over 300 whales were killed annually. Now the industry operates with a quota of 8 for the Sea of Japan, 2 for the southern Okhotsk Sea and 52 for the Pacific coasts (Kasuya 2002).

Incidental catches have been recorded, but are generally not common. Some Baird's beaked whales have been caught in Japanese salmon driftnets (Reeves and Mitchell 1993).

This species, like other beaked whales, is likely to be vulnerable to loud anthropogenic sounds, such as those generated by navy sonar and seismic exploration (Cox et al. 2006)

Predicted impacts of global climate change on the marine environment may affect this species of whale, given its cool-temperate to sub-polar habitat, although the nature of likely impacts is unclear (Learmonth et al. 2006).

There has been no agreement in the IWC on whether or not it has the competence to classify or set catch limits for this species, even though it is included in the IWC definition of "bottlenose whale" (the only species so regulated is the northern bottlenose whale, Hyperoodon ampullatus). At the 2000 annual meeting of the IWC Scientific Committee, Japan explicitly expressed its unwillingness to subject its research and management program for this species to international scrutiny (IWC 2001).

Although the IWC does not control the annual quota of Baird's beaked whales, it is assumed that the present catch levels over a short period would not seriously affect the subpopulation, but research is needed to obtain information that will allow a full assessment of its status.